The Blues Deluxe Reissue comes standard with 12AX7s in V1, V2, and V3. I currently have the "Blues" retube kit from Eurotubes which uses a 12AX7 and V1 and V3 and a 12AT7 in V2. It sounds great. I have also heard of people using a 12AX7 in V1 and V2 with a 12AT7 in V3. Then there is the 12AY7 in V1 and 12AX7 in V2 and V3.

I prefer lower gain in the BDRI while getting my overdrive sound from my modded Boss BD-2 and OD-3.

I tried swapping the 12AT7 in V2 with the 12AX7 in V1 in my BDRI and did not like the sound. Although the S/N ratio was better, it sounded too clean to the point of being sterile and brittle so I swapped back.

I have read several recommendations for a 12AT7 for the PI in Hot Rod amps on this and other forums. I believe that is what the BF amps use?

The 12AY7 I was curious about as I believe that was what was used in V1 in the original 57 Twin/59 Bassman.

The tinkerer that I am is interested in trying other tube combinations, but before I drop the bucks on tubes, has anyone else tried different combinations? If so, I am curious about your results. Please share.

BTW: I used the 12Axx designators instead of the proper ECCxx designators that JJ uses because I can never remember which is which.

12AT7s (and 12AU7s) were not designed as audio amplification tubes, but as drivers, which is what the PI does, so I recommend trying that out. Bear in mind that a couple years ago when I was tube swapping in an Epi Valve Junior, I tried 7 or 8 'preamp' tubes, including RCA and Mullard 12AX7s from the 60s, some current production Sovtek/EHs, as well as other designations (AU/AT7) and liked a used TungSol AU7 the best...UNTIL I got my hands on real NOS 12AY7s, and that was all she wrote.

12AY7 have a bit less than half the gain of a 12AX7, which allows us to turn the amp up louder before the distortion sets in. Mind you, it will still be making the same amount of power, in your case 40ish watts with the MV all the way up, when that happens, but you'll be able to turn the amp up to something like 5 or 6 instead of 2 or 3. Use a pair of them (V1 & V2), and you'll really be able to open things up regarding the knobs...still 40 watts, but what I find is better control over the edge of distortion tones that I like.

Combine all that with variations in bias (not sure if the BDRI has adjustable bias, pretty sure the originals did not) and there are tons of tonal possibilities available.

Yes, most BF amps, to the best of my knowledge, came with 12AT7s as PIs, and usually as reverb drivers, as well.

I also suspect you're right that many of the tweeds came with 12AY7s in V1. I think Leo was processing on the assumption that the lower gain would mean a) lower signal to noise ratio and b) that no one would want to drive the amps into distortion on purpose. Oops.

12AT7s (and 12AU7s) were not designed as audio amplification tubes, but as drivers, which is what the PI does, so I recommend trying that out. Bear in mind that a couple years ago when I was tube swapping in an Epi Valve Junior, I tried 7 or 8 'preamp' tubes, including RCA and Mullard 12AX7s from the 60s, some current production Sovtek/EHs, as well as other designations (AU/AT7) and liked a used TungSol AU7 the best...UNTIL I got my hands on real NOS 12AY7s, and that was all she wrote.

12AY7 have a bit less than half the gain of a 12AX7, which allows us to turn the amp up louder before the distortion sets in. Mind you, it will still be making the same amount of power, in your case 40ish watts with the MV all the way up, when that happens, but you'll be able to turn the amp up to something like 5 or 6 instead of 2 or 3. Use a pair of them (V1 & V2), and you'll really be able to open things up regarding the knobs...still 40 watts, but what I find is better control over the edge of distortion tones that I like.

Combine all that with variations in bias (not sure if the BDRI has adjustable bias, pretty sure the originals did not) and there are tons of tonal possibilities available.

Yes, most BF amps, to the best of my knowledge, came with 12AT7s as PIs, and usually as reverb drivers, as well.

I also suspect you're right that many of the tweeds came with 12AY7s in V1. I think Leo was processing on the assumption that the lower gain would mean a) lower signal to noise ratio and b) that no one would want to drive the amps into distortion on purpose. Oops.

Good Luck

Excellent information. Thanks. I might try the AT7 in the PI and an AY7 in V1.

Yes, the BDRI has adjustable bias. I have that dialed in just where I like it.

For my experimentation of preamp tubes in my Blues Deluxe Reissue, I have chiefly relied on the recommendations of Derek Rocco, who is apparently the main guy at Watford Valves, a respected tube outlet in England. He has written about tube rolling using his Hot Rod style, Blues Deluxe Reissue.

Since I would assume, given his position, that he has the ability to widely experiment with tubes in all of the preamp tube positions in these types of amps. I think his recommendations sound great.

Specifically, Derick has written:

Quote:

I have been using a Blues Deluxe Reissue to evaluate amp and the speaker combinations. The reasons for this is that in November 2007 we will be bringing out an extension cab for this. This I feel is a great amp.

I used a 5751 in V1 and V2 with a balanced harma 7025 in V3. The 6l6 i liked the best was the Philips 6L6WGB, BUT FOR CLEANER SOUND I WOULD USE THE WINGED C SVETLANA 6L6GC."

The 7025 that Derick is using in the V3 phase inverter slot is essentially a high quality, high gain 12AX7, similar to a Tung-Sol 12AX7. Derick is also using JAN Philips 5751's in V1 and V2.

I recommend trying two 5751's in V1 and V2 and a 12AX7 in V3, as I find this combination, quiets the amp, provides greater headroom (Bass control moves from 4 to 12, the other control settings may remain the same) and sounds great once you adjust to the change. The 12AX7 in the V3 phase inverter, still gives you some balls.

12AT7s (and 12AU7s) were not designed as audio amplification tubes, but as drivers, which is what the PI does, so I recommend trying that out. Bear in mind that a couple years ago when I was tube swapping in an Epi Valve Junior, I tried 7 or 8 'preamp' tubes, including RCA and Mullard 12AX7s from the 60s, some current production Sovtek/EHs, as well as other designations (AU/AT7) and liked a used TungSol AU7 the best...UNTIL I got my hands on real NOS 12AY7s, and that was all she wrote.

12AY7 have a bit less than half the gain of a 12AX7, which allows us to turn the amp up louder before the distortion sets in. Mind you, it will still be making the same amount of power, in your case 40ish watts with the MV all the way up, when that happens, but you'll be able to turn the amp up to something like 5 or 6 instead of 2 or 3. Use a pair of them (V1 & V2), and you'll really be able to open things up regarding the knobs...still 40 watts, but what I find is better control over the edge of distortion tones that I like.

Combine all that with variations in bias (not sure if the BDRI has adjustable bias, pretty sure the originals did not) and there are tons of tonal possibilities available.

Yes, most BF amps, to the best of my knowledge, came with 12AT7s as PIs, and usually as reverb drivers, as well.

I also suspect you're right that many of the tweeds came with 12AY7s in V1. I think Leo was processing on the assumption that the lower gain would mean a) lower signal to noise ratio and b) that no one would want to drive the amps into distortion on purpose. Oops.

Good Luck

I put a set of Tung Sols in my BDRI, and it made that amp come to life!

IMO the best preamp tubes for the reissue are tubes that came with the original blues deluxe when they came out in the mid 90s. Great sounding amp stock back then and even 10 years later. Bias the amp to run hot and it will sound it's best.

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Theres nothing to be cautious of here...the tube is simply a combination of other tubes which are also safe in this amp. I contacted Bill M and he advised me of this "trick"-which I tried and am thrilled that I did.

In the HRD the drive channel is influenced by V1 and the second half of V2 and it makes for an improved drive channel, without a change to the great cleans of the amp. It makes the drive into a great bluesy drive on the HRD. The Blues deluxe is a similar design and may also benefit-I believe the preamp is quite similar, and NOS 12 dw7s are pretty affordable. This amp is an exception to the "in general" qualifier you used.

Your quote on the mids and bass in HR amps are true in any stock amp-its the way the HRD tonestack comes stock, not because of a preamp tube.

And in the phase splitter slot there you are right-its quite unbalanced but that may be a good thing to some-in fact many harp players run a 12dw7 because it gives a very raw sound to the amps they crank.

Theres nothing to be cautious of here...the tube is simply a combination of other tubes which are also safe in this amp. I contacted Bill M and he advised me of this "trick"-which I tried and am thrilled that I did.

In the HRD the drive channel is influenced by V1 and the second half of V2 and it makes for an improved drive channel, without a change to the great cleans of the amp. It makes the drive into a great bluesy drive on the HRD. The Blues deluxe is a similar design and may also benefit-I believe the preamp is quite similar, and NOS 12 dw7s are pretty affordable. This amp is an exception to the "in general" qualifier you used.

Your quote on the mids and bass in HR amps are true in any stock amp-its the way the HRD tonestack comes stock, not because of a preamp tube.

And in the phase splitter slot there you are right-its quite unbalanced but that may be a good thing to some-in fact many harp players run a 12dw7 because it gives a very raw sound to the amps they crank.

The op asked for interesting preamp tube ideas-this is certainly one.

To each is own.

I don't know who Bill M. is, but I've never seen anyone that I would consider an expert on amps recommend the use of a 12DW7 in any preamp slot, in any amp, but apparently the idea is for some unknown reason, generating a buzz on these threads.

With all of the other choices for preamp tubes, I don't understand why anyone would want to use a completely unbalanced preamp tube.

Go on the Tubestore page for the 12DW7 and you will not find any recommendation that these tubes are a substitute for a 12AX7. And I've never seen any authoritative source that suggests that either.

If you can direct me to any authoritative source which states that the 12DW7 is an acceptable substitute for a 12AX7, I would love to take a look at it.

This is a suitable replacement for any 12DW7 / ECC832. One side has a gain factor of 100 - the other side has a gain factor of 20. You can think of it as 1/2 a 12AU7 and 1/2 a 12AX7. Try this tube for some interesting gain reduction effects on certain amps.

There are legit reasons for wanting to tinker with this amp. Im simply making the op aware of a cheap, reversible mod that may take his drive side from something hes not happy with to something that he may like-even if tubestore didnt mention it.

Wow! Just realized I haven't been back to this thread since January. Here is the final tube configuration I settled on:

V1 - Phillips/JAN 5751
V2 - JJ 12AX7
V3 - JJ 12AT7
V4/5 - JJ 6L6GC

Bias is set to 38 mA cathode current/approx 36 mA plate current with a plate voltage of 413 VDC. Well broken in stock Fender/Eminence speaker.

I plug my SCN equipped Strat into input #1 and use the clean channel. I plug my two humbucker equipped guitars into input #2 and use the drive channel as a second clean channel with the levels matched to the clean channel. The amp sounds sweet as honey and the signal to noise ratio is greatly improved. I use a Fulltone Full Drive 2 MOSFET for dirt with all three guitars. The FD2M is my only pedal (besides a Boss TU-3) and is all I need to play the Blues.

Wow! Just realized I haven't been back to this thread since January. Here is the final tube configuration I settled on:

V1 - Phillips/JAN 5751
V2 - JJ 12AX7
V3 - JJ 12AT7
V4/5 - JJ 6L6GC

Bias is set to 38 mA cathode current/approx 36 mA plate current with a plate voltage of 413 VDC. Well broken in stock Fender/Eminence speaker.

I plug my SCN equipped Strat into input #1 and use the clean channel. I plug my two humbucker equipped guitars into input #2 and use the drive channel as a second clean channel with the levels matched to the clean channel. The amp sounds sweet as honey and the signal to noise ratio is greatly improved. I use a Fulltone Full Drive 2 MOSFET for dirt with all three guitars. The FD2M is my only pedal (besides a Boss TU-3) and is all I need to play the Blues.

That should work!!

I'm very happy with my sound with Jan Phillips 5751s in V1 and V2 and a Tung-Sol 12AX7 in V3.
I also use Fender SCN pickups in my 3 Teles and a Strat (I like the Tele pickups even better than the Strat).
The amp is so completely quiet, with no hiss or hum, that you don't know that the amp is even on if you are not playing.

I recently ordered a 12AT7 to try in V3, after posting in some of these BDRI threads on preamp tubes, just to experiment.
I have the feeling that this might be too much of a gain reduction without going to a 12AX7 in V2, as you have done.

Either one of these preamp combos are probably the ticket for this amp!!
Glad to see that you stayed away from that 12DW7 nonsense.

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